The present invention relates in general to a hose clamp, and, more particularly to a hose clamp for coupling a flexible hose, or the like, to a receptacle therefore or to another length of hose.
Hose clamps are commonly used for the purpose of coupling a length of a flexible hose, or the like, to a receptacle in fluid communication with, for example, another length of hose or a fluid container. In general, conventional hose clamps, e.g., band clamps or segmented clamps, provide a compression force that deforms the compliant hose material against the exterior surface of the receptacle to establish a seal therebetween. Hose coupling devices, particularly those employing conventional hose clamps are well known in the art. For most applications wherein fluid, i.e. a gas or liquid, is provided under a relatively low pressure through the hose, the seal established between the hose and receptacle by a conventional clamp is sufficient to prevent leakage or unintended separation of the hose from the receptacle.
It has been recognized, however, that conventional hose clamps are inadequate for use in high-pressure fluid applications requiring, for example, a 150 p.s.i. working pressure and 600 p.s.i. burst pressure on a 6xe2x80x3 diameter hose. Conventional band clamps generally exhibit insufficient clamping force for high-pressure applications. Segmented clamps generally provide a high clamping force, but are deficient in other aspects.
For example, one reason for the failure of conventional segmented hose clamps in these applications is that they generally fail to provide an even distribution of compression force against the exterior surface of the hose. Typically, segmented hose clamps are generally annular in form with one or more ridges or compression rings on the interior surface of the clamp. The hose is positioned with its interior surface against the exterior surface of the receptacle, and the clamp is tightened around the hose with the ridges or compression rings providing or adding to the compression force against the hose. The hose is thereby deformed against the exterior surface of the receptacle, which may have indentations or ridges therein in areas that correspond with the ridges or compression rings on the interior surface of the clamp.
Unfortunately, the ridges or compression rings on the clamp provide a localized compression force against the hose. In low-pressure applications, this localized force is sufficient for maintaining a seal between the hose and the receptacle. However, in high-pressure applications, the forces created by the fluid passing through the hose and into the receptacle can overcome the localized compression force and dislodge the hose and clamp from the receptacle. This can result in undesired spilling of the fluid, which, depending on the nature of the fluid can create a potentially dangerous situation. Also, as the clamp is dislodged from hose, the clamp may be projected at a high velocity in the direction of fluid flow, potentially resulting in property damage and/or severe physical injury.
Another aspect of conventional segmented clamps that attributes to their lack of utility in high-pressure applications is their lack of adaptability to account for tolerance variations in hose and receptacle diameter. Typically, a segmented hose clamp is configured for clamping a hose having a pre-determined outside diameter to a receptacle having a predetermined outside diameter. When the hose and receptacle do not match their predetermined diameters due to manufacturing tolerances, the clamp may be slightly oversized or undersized. This results in an uneven distribution of the compression force against the hose that can precipitate leakage or unintended separation of the hose from the receptacle under high fluid pressure. Again, the rupture and the spillage associated therewith can result in physical injury and property damage.
Accordingly, there is a need in the art for a hose clamp that may be utilized to efficiently and reliably secure a flexible hose or the like to a receptacle or to another hose when fluid is passed through the hose under high pressure.
The present invention is organized about the concept of providing a hose clamp that establishes a reliable, fluid-tight, seal between a hose and a receptacle or another length of hose in relatively high-pressure fluid applications, e.g. 150 psi working pressure. A clamp consistent with the invention provides distributed compression force on a hose using a plurality of clamp segments and a span ring, e.g., a spiral wound ring. Each clamp segment includes an arcuate interior surface having a span ring slot therein positioned to align with a corresponding span ring slot in an adjacent clamp segment. Each clamp segment further includes a bore in a first end thereof which is adapted to align with a corresponding bore in an end of an adjacent segment.
Upon installation, the hose is positioned over a receptacle, and the clamp segments are oriented around the hose with the span ring disposed in the respective span ring slots. A fastener, e.g., a screw, may be inserted into the bores to draw the ends of the clamp segments toward each other, thereby tightening the segments of the clamp around the hose and receptacle. As the clamp tightens around the hose, the diameter of the span ring changes so that the top surface of the span ring is approximately flush with the interior surfaces of the clamp segments. Thus, in contrast to the prior art wherein a localized compression force is established by ridges or compression rings on the interior surface of the clamp, in a clamp consistent with the present invention a distributed compression force is established primarily by the pressing engagement of the interior surfaces of the clamp segments against the hose.
Advantageously, the clamp segments are dimensioned relative to the expected diameter of the hose so that when the clamp is installed, a space is provided between the ends of the clamp segments. This arrangement facilitates compensation for variations in the expected diameter of the hose and receptacle due to manufacturing tolerances. As the clamp is tightened around the hose, the independence of the clamp segments relative to each other allows the clamp segments to flex slightly to conform to the exterior surface of the hose. The span ring extends across the spans between the clamp segments to maintain compression in the areas of the spans.
More particularly, a distributed force hose clamp consistent with the invention includes a plurality, e.g. three, of separate clamp segments, each of which has an interior surface with a span ring slot therein. Each of the clamp segments may be constructed of aluminum, and may be generally arcuate with a generally rectangular cross-section having chamfered top edges. The interior surfaces of the clamp segments may define a portion of an arc approximately equal to 360xc2x0 divided by a total number of clamp segments.
A clamp consistent with the invention further includes a spiral-wound span ring having separate portions disposed in each of the span ring slots with an interior edge of the span ring approximately flush with an interior surface of each of said clamp segments. The span ring has at least one portion spanning at least one space between adjacent ones of the clamp segments.
The segments may be joined around a hose in a variety of manners to create a compression force between the interior surfaces of the segments and the hose. According to one exemplary embodiment, however, each of the clamp segments has a first end with a first fastener bore therein and a second end with a second fastener bore therein. The segments may be joined using fasteners, e.g., screws. Each fastener may have a portion disposed in one of the first fastener bores and a second portion extending into one of the second fastener bores for releasably joining the clamp segments in an end-to-end configuration.
A method coupling a hose to a receptacle consistent with the invention includes the steps of: providing a hose clamp consistent with the invention, positioning the span ring and the clamp segments over the hose with the hose disposed between the interior surfaces of the clamp segments and said receptacle; and placing the interior surfaces in compression against the hose to compress the hose against the receptacle. The interior surface may be placed into compression against the hose by threading fasteners into respective first and second fastener bores of adjacent clamp segments.
Coupling one hose to another hose consistent with the invention includes the steps of: providing a first hose clamp consistent with the invention, positioning the span ring and the clamp segments of the first hose clamp over the first hose with the hose disposed between the interior surfaces of the clamp segments and one end of a hose coupling device dimensioned relative the diameter of the hose; and placing the interior surfaces of the first hose clamp in compression against the first hose to compress the first hose against the hose coupling device. These steps are repeated for the second hose using a second hose clamp to compress the second hose against the other end of the hose coupling device. The hose coupling device may be constructed of plastic or metal, or other material of sufficient strength to withstand the distributed compression force of the invented clamp. Not only can hoses of the same diameter be coupled in this fashion, the invented clamp can be used to join hoses having different diameters by using a hose coupling device having different diameters at either end to accommodate the respective diameters of the hoses to be joined.